Clutch control mechanism



Aug. 17, 1943.

E. G. HILL. 2,326,943

CLUTCH CONTROL MECHANIS M 2 Sheets-Sheet l Filed July 8 1941 Aug. 17, 1943.

2 Sheets-Sheet 2 Filed July 8 1941 Patented Aug. 17, 1943 Y 2,326,943 v v .CLUTCH CONTROL MECHANISM a y A Edward G'. Hill, Richmond, Va., assignorYto-Hill Engineering Corporation, Richmond, Va., a corporation of Virginia,

' Application Ju1vy-s,194r1, seria1N.4t1,513f

` v32 Claims.; (erica-.01;

This. invention relates to clutch control mechai" nisms.- Y'

.The present invention contemplates the Yuse of a fluid pressure operated clutch control motor having a .control mechanism of theV type shown in my prior Patent No. 1,964,693 wherein a fol-` 10W-up valve controls the admission `of. air into the clutch motorY to` deene'rgize the latter and thus release the. clutch elements for movement toward each other.' They follow-up valve of myk priorconstruction isofluid'pressure controlled in accordance With pressure l differentials in^the clutch 'motor this type offfollow-up'valve beingV found highly advantageous for the reason that fl5v it providesv for the. automatic checking ofthe movement of the `clutchelements into engage- .ment, such"movement being vretarded if the acmechanism kbeing operable upon ,depression of the accelerator pedal for effecting clutch engagel .ment. y In-,order to prevent disengagementpl.A the 'a clutch when the vehicle is in high gear'- and trav-v 4 "elling above a predetermined speed, whichisde sirable to prevent freegwheeling `undersuch conditions and to, permit }the. use of the Vehicle en gine asa. brake, th-'prior constructions prefercelerator,iscontinuouslyfdepressed and` being arrestedv if ki'rmvement of the accelerator pedal is stopped yprior to clutch-engagement. i

The prior construction referred .to has been' found to provide a highly eicient single control `valve mechanism lfor properly controlling engagement of the clutchelernents under mostoperating.; conditions and is capable` of operation to provide Very efficient clutch engagement in the normal shifting operations through which arvehicle transmission passes in starting from astandstillandgoing successively into first, second and third gears. It is possible to cause clutch eny gagement to takeplace too rapidly With the prior construction referred to if the accelerator pedal.

is depressed too rapidly in first, second or reversevgears, and several effective rwayshave been proposed in which totake care of clutch engagement under such conditions to prevent too rapid clutch engagement. For eXampl, -`in lthe cependingapplication of-Edward G; Hill andA Henry HeyfSerialNo. 369,498, iiledDecemberlO, 1940, there vis disclosed a` clutch control mechanism myl priorpatent referred to, ,but` provided with auxiliary means fory varying: the loading vof, the spring associatedvwthy thek iluidl pressure operated folloW-up valve to causefailagging lof the to the accelerator pedalto move the valve. mech` anism to Aai clutch-releasing 'position when the accelerator pedal is in idling positionfthe valver 40 employing a control valveof the type shown in v' ably. have been employed in connection with fa. vsysteml for 'cutting off the valve mechanism. ,from the source ofpressure diiferential when the transmission is inhiglrgear with the vehicle" or .the vehicle enginetravelling above af predetermined speed. The speed responsive means'may be'of any desired type. suchl asv thatl shown infthe prior patent to Edward G.Hil1 and Henry We Hey, No'. 2,049,738', or it may be of anyother..k desired type, for example, in-'the forni of agov `ernory operated mechanism'driven by the vehicle 'propeller shaft or any other suitable part of the motor-vehicle.V e

The combination of the vanoussys'temsreferred to provides a highly efficient *clutch-c0113` trol mechanism for properly veffecting-clutchen-Vv gagement after each gearshifting operationen-` cept kparticularly that condition which exists when a shift down is to'be made fromrhighto` y second gear. Under suchconditions thevehiclev engine is rotating at a vmuch lower speed in high', y gear than willfbe.required-afterfthe shift clownv v In the @pending application of Edward G. Hill and I-IenryW. Hey, serial No. 372,410, filed December 330, 1940, there is shown and described a .system for causing a substantial. lagging of themovehas been Amade from high to second-gear,

ment of the clutch elements intooperatiVe en?, gagement when, a shift is made `from high-to second-gear to permit substantial engine acceleration to take place prior to engagement-of the clutch l elements. v

' is to provide a clutch control mechanism-having vThe prior constructionsreferred tok'allk provide means connecting the control. valve mechanism a Vhighlyimproveol means for facilitating a shift. from high to second gear wherein a substantial time' lag occurs before clutchengagement takes placeto permit the vvehicle engine to properlyaccelerate. `.A further object highto second gearbut doesnot normallyoccur When'ashift is vbeing made from `irst into sec-` ond gear, thus :permitting relatively rapid clutch is to provide Lsuch af-clutch control mechanism wherein the meansreferred to functions when the shift down is made from `ployed for rocking the shaft I4.

thus permits engine speed to drop to an idling speed, the time delay under such conditions permitting engine acceleration to take place prior to clutch engagement to prevent jerking of the vehicle or the stalling of the engine.

A further object is to provide an auxiliary control device for a clutch control mechanism'v in the form of a solenoid switch which functions, when energized, to permit normal clutch engagey ment to'talre place and which iunctions'when I ing, an annular groove 31 throughout the greater deenergized to close a circuit causing `lagging f movement of the clutch elements into engageto clutch engagement, the auxiliary control device being constructed to provide a time interval between its initial deenergization andthe closing ofthe circuit which provides the lagging clutch engagement.

ment to permit time for engine acceleration prior c Other objects and advantages of the invention will become apparent during the course of the following description.`

In theA drawings I have shown one embodiment ofthe invention. In this showing-'- Figure 1 is a side elevation of a motor vehicle power plant showing the kclutch control mechanism connected thereto,

Figure 2 is a central vertical longitudinal sec,- tional view through the control valve mechanism and associatedelements, parts being shown in elevation and parts being broken away,

Figure 3V is a diagrammatic representation of the electrical control system for the apparatus; and, Y

Figure 4 is adetail sectional view cf the auxiliary solenoid switch device.

Referring to Figure 1 the numeral vIt* designates a motor vehicle engine having an intake manifold II to which explosive mixture is supplied through aconventional carburetor I2. The engine is provided with the usual clutch indicated as a whole bythe numeral I3 and having the clutch elements thereof (not shown)` controlled by the usual rock shaft I4to which is'connected an -operating crank I5. Power is delivered from the clutch through a transmission I6 having theusual shiftable elements for providingcon-ventional gear ratios. Referring to Figure 3 the shiftable elements have been indicated as comprising a second and high gear shift rail I1 and a low and reverse gear shift rail I8. These elements, of course, maybeconventional except as slight alteration is required therein for the proper functioning of the present mechanism.

A` differentialfluid pressure motor `I9 is em- This motor comprises a cylinder 2!) having a piston 2-I therein connectedby a connecting rod-22 tothe lower end of the crank I5;v The end of the cylinder 26 toward the crank I5 isv open to the atmosphere as will lbe apparent and-the other end of the motorie connected to a vacuum conduit 23. The motor I9 is provided with an arm'24 pivotally connected as at 25 to a supporting bracket 26, the pivotal mounting of the motor permitting the swinging ofthe motor tc accommodate itself to ing-a cylindrical'valve 32. This valve is providedf withxports` 33 communicating between the interior ofthe valye 4and the space between4 the landsx29l and 3D. 'The valve 32 is further proportion of its length and constantly communicating with theports 33 as will become apparent. "The groove or space 31, under conditions to be described is adapted to communicate with the ports 34 and thus connect themotor cylinder 26 to the source of pressure differential. To complete such connection, it will be noted that the space between the lands 29 and 30 communicates with apassage 31 controlled by a valve 38 which is the armature of a solenoid 39, and a spring'40 urges the valve 3,8V to the closed position shown" in Figure 2. The outer end of the passage' 31 is connected by a pipe 4I to the intake manifold II, the latter constituting the preferred source of pressure` differential.

A cap 42 (Figure 2)'is threaded in one end of the'valve body 28 and slidably receives a valve operating rod 43. The main valve 36 has an axial opening 44 extending throughout its length and the rod 43 extends into this opening and is pinned to the valve 36 as at 45. Movement'o-f the rod 43 to the left as viewed in Figure 2 connects the groove 31to the ports34 thus energizing the motor I9 tov disengage the clutch, and means is provided for causing the Valve 32 to vfollow-up with respect to the valve 36; A diaphragm 46 is clamped between the anges 41 and 48 respectively of a circular enlargement 49 formed integral with the valve body `28 and a cap 5U. The enlargement 48 and cap 50 cooperate with the diaphragm 46' to form chambers 5I and 52 the former of which co-mmunicates with the space to the left ofthe land 3 I which space communicates' with the interior of the valve 32 through ports 53 formed in such valve.

The diaphragm 46 is secured to the adjacent end of the follow-up valve 32 by a screw 54. This screw extends through a spring seat 55 engaged by a compression spring 56 the other end of which engages a spring seat 51. The spring 56 lurges the valve 32 toward the right as viewed in Figure 2. The chamber 52 communicates with the port 35 through a passage 'and accordingly it will be apparent that When the motor cylinder 26 is connected to the source offvacuum, a reduction in pressure in the chamber 52, will occur. This reduction in pressure will correspond to that in the vacuum end of the motor cylinder 20 and atmospheric pressure in the chamber 5I will overcome the tension of the spring 56 to move Vthe follow-up valve 32 to the left a distance corresponding tothe extent to which pressure is reduced in thechamber 52. l 'I The spring 56 has' a normal l tensioningV to cause a proper follow-up action of the valve 32 verse gears, thus increasing the loading of the idlingnosiiicm...y

Spring; 5B1-to causeLthe follow-upzvalve' 42 :to oc.- cupy a. position further ftol'theright. as. viewedv inFigure-Z forl any givenfdegree ofpar-tialvacuum in the chamber 5.2. 'I'his causes a lagging of clutchI engagement'inja mannerV to be ldescribed. ufff-:I: .I

In accordance with the disclosuresgof. the .prior applications.` referred to, a? leverfZ. isfconnected toa shaft 63 `of '.the"`icarburetor" throttle `(not shown) .and this-lever has an offset arm S4-.conf

nected. by arodv 6,5 to; the fuel injector pump |555 whichfof course,;is conventional in present day f carburetors.; i A secondjlever 'Blais pivotedv as at.E

68 to the lever IGZ `and a swivelzl connects this lever, tothe rod 43.' The 'lever` 6] has a projection lfengageablewith ;theupper'end ofthe 1 arm l'after .predeterminedjturning' movement of the lever ..61 ,abouti'itsgpivotf63.1 This move ment; takes place -independently of the lever 02. This lfindeizaendent movement is provided for operatinggthe valve independentlyoffthe carburetorgthrottle and whenf the` projection I0 engages. ,thef arm 64; rurthen movement imparted to theljeveri 'lfwill move this lever andthe lever..

62;as aunitfto' open the eng-ine throttle. l :A link 1I is y connected to the lever 62 approximatelymidway between the-pivot 68 and swivel. 69.uThe link II is connected tothelow.er end Y oran arm. 12 of a bell Ycrank leverfIS, this lever being-pivoted on the engine 'I0-rasato and be.- ing:l provided;with,.afrsecondg arm J5 :connected by a-rod .16 to -theaccelerator pedal 'I'I. kA, spring a I8 urges the accelerator pedal, upwardly toward jThe time delay'means for retarding clutch en,`

gageinent -to allow-g time. for engine 4acceleration tdtake place when .ashift is made'from highvtop. second gear ispreferably electrically controlled in a manneroto bedescribed and may be assoelated wtih the throttle control levermechanism, Shown-in Figurezl, for-example, .by-means ofy .a

cam engageableavith,theflever `6 1 to limit inde-v o pendent turning movement thereof` with respect to the lever 6'2, as shown in the copending applicationcof Edward Hill and `Henry W. kHey,

Serial No.-..372,4 =10, referred torabove. vIn they present case the means for causing'. a substan.- tial lagging movement .ofi-the clutchl elements intol engagement vunder the Vccnfiilitioris referred f to has been shown in the form-ofadevice for chokingoi the admission oi?v air into,` the motor..

cylinder .20 ,when vthe accelerator f is operated to move the valve mechanism in Figure 2 to a clutch:

releasingpostion. n l Y .y

Referringto .Figure -2 it will `rbenoted that the valve,` passage 44 is in constant communication with the space 82 within .the valve casing 2 8, adjacent the cap` A2. Thistspace communicates .y through a port.-,83.with a passage iid-normally',

open to the atmosphere,andpreierably provided with ya' small .air` cleaner 85.

passage 85 to permit free movement of air there through and the valve 80 forms-.the arma-ture of` the solenoid 88 energizable l to move the valve to the right as viewedin vFigure 2. to tl'ieclosed position., Aspring. 85` tends Lto ,holdthe .valve Y 85in .normalpositiorrand when the valveis in A f theclosed positionfrefer'red 5to, asmall groove 90 around the head endof thegrvalve yprovidesa restricted communication `through `the passage 84..-g Aocording1y, when the I follow-up lvalve mechanism is movecltoy admit air'into the motor cylinder V20to releasevthe clutch, the-ollow-up Valve mehanismcomplelielr controls-.the ratenf..

o A valve Sli hasta.;` reduced stem 8l normallyextending across the clutch engagement vexcept ,when thevalve 06 is closed', in which case the rate of clutch engagef 'ment is determinedby ythe rate'v of admission of air around thegroove of the valve 86.

In Figure 3 of the drawings there ,isV shown I an electrical controlsystem `lor the apparatus, and'ithis system includesa solenoid controlled switch fdevice for determining .the energization y of the solenoid 88 just described. Referring to 10 Figure 3, the-'source of current-0I vmay be the vehicle battery and one side of the source `is grounded as at 92. A wire '93 'connects the other terminal Vof the source to aswitch arm SIIIl er1-'- gageable with contacts 95 and 96, depending upon f vehicle speed.A The switch arm 94 is preferably governor controlled in accordance with vehicle. speedl in any suitable manner and preferably engages the Contact 95 at vehicle speeds below 10 milesr per hour; This speed is preferred but any predetermined speed ,may be adapted to errgage the switch 94 withjthe Contactl 95, and at. all higher vehicle speeds the switch arm Slt en-` gages the contact 95.

The contact5-isconnected by a wire 91 toa contact'88 engageable by a switcharm 9S when the shift rail I `I is in the yhigh gear position. For

any` other-position of the high gear shift rail,

the switch armSSengages a second contact |00.

The shiftrail I 'I is shown as having an insulated end 0I engageable'withvthe switch arm'99 to move itintoy engagement with the contact. .98 f

without grounding the latter Contact on the transmission,l the later being shown as being I grounded as at |02.V The switch arm 90 is connec/tedby a Wire |03 to one terminal of the solel noid `38 and the other `terminal of this solenoid is grounded as at |04. When the switch arm 98 is in engagement with .the Contact |00, current ilows to `the .latter contact through a wire |05 connected between the contact |00 and the wire93.

YThe low and reverse gear shift rail I8 is providedvwith. a pair of rings |05 and |01 selectively engageable with a contact |08` connected to one end of Aa, wire I0!) leading tothe solenoid 60. The contacts '|05 .and VIIlI are respectively enraill I8 is in lowor reversegears. offsuch conditions the solenoid will be ener'- gized to increase the loading of the spring 56 (Figure 2) as previously stated. When so ener-y gized current flows through the Vsolenoid B0 by meansl of awire I I0 connected to one terminal of the solenoid indicatedl as a whole by Vthe numeral |,II andpreferred to in detail below. From the second terminal orf.v the ,solenoid III a Awire |I211eads-to the Wire I 05. I

solenoid I II comprises a coil I|2 having a core I I3 in which is movable an armature, this armature being slightly smaller than the internal diameter ofthe corey I3 for a purpose to be-de-K` The armaturev I I4 moves upwardlyuponeneri gization of the coil II2y and downwardly when the coil is deenergized,and the speed of down- I gageable withy they contact |08 when the shiftl Under either l .Referringto Figure 4, it will be noted that theward movement of the armature is dependentk upon the area4 of the space between the armature and the core |I3 and the viscosity of the oil I'I1. These elements are so related tov each other that itpreferably requires four seconds for the armature I I4 to move to its lower limit of move'- ment from' the' upper limit of movement shown in- Figure 4. Upward movement of the armature I4 and the elements connected thereto is limited byA engagement of the head |20 with the flange IIE.

When the solenoid I is deenergized the-head |20 moves downwardly in the manner described to engage a pair of contacts |2| and |22 the former of which is connected by a wire `|23 to a switch element |24 engageable by the shift rail I1 when the latter is in the second gear position. The contact |22 is connected by a Wire |25 to one terminal ofthe solenoid 88 and the other terminal of this solenoid is connected by a wire I 26 to the contact 96. i

It will become apparent that when the vehicle is in high gear and travelling above the predetermined speed at which the switchv 94 leaves the contact 95, thek releasing of the accelerator pedal will not effect clutch disengagement, the

clutch remaining engaged to permit the engine to be used as a brake. In order to provide for clutch disengagement under such conditions in order to shift back from high to second gear, it is necessary to provide means for overruling the governor switch 94 and the overruling means may be of any desired form. For example, the overruli'ng meansmay be in the form of a gear shift leverswitch as shown in the copending `application f Edward G. Hill and Henry W. Hey, Serial No. 372,410. The particular type of overruling means is not important, and for the purpose of illustration the overruling switch has been shown diagrammatically in Figure 3 and has been indicated by the numeral |21. This switch is connected by a wire |28 to the wire |05 and is engageable with a contact |29 connected by a wire |30 tothe wire |03.

The operation of the apparatus is as follows:

The clutch control valve mechanism shown in Figure 2 functions upon operation of the accelerator pedal in the same manner as the priorV constructions referred to and need not be described in` detail. Generally speaking', it will be obvious that, except under conditions to be described, the releasing of the accelerator pedal effects declutching, and depression of the acceleratcr pedal releases the clutch elements for movement into operative engagement. Disengagement of the clutch elements, of course, is effected before each gear shift and clutch engagement is effected after each shift has been completed, in accordance with conventional practice.

When the accelerator pedal 11 is released, the bell crank lever 13 will be turned in a clockwise direction` to move the levers 62 and 61 until the throttle carried by the shaft B3 reaches idling position whereupon the lever 61 will turn in a counterclockwise direction about its pivot 68, independently of the lever 62. Such movements of the lever mechanism effect movement of the valve operating rod 43 to the left as viewed in Figures l and 2 and resultsin bringing the space 31 (Figure 2) into communication with the ports 34 while closing these ports to the air passage 44. Air will then be exhausted from the vacuum end of the motor cylinder 20 through pipe 23, port 35, ports 34,4 vacuum space` 31, ports 33,-

enamora z passage 31.' and` pipe 4|". course, assumes` that'the valvey 38 isopened and this isl true except under conditions to be described.

As air is exhausted from the' clutch motor it likewise will be similarly exhausted from the diaphragm chamber 52 (Figure 2) through passage 50V and air pressure inthe chamber 5I will move the diaphragm 46' to the left. This operation obviously moves the valve 32 to the left to cause it to partake of a follow-up action with respect to the valve 36. Accordingly the extent to which the valvev 36 is moved will be accompanied by similar movement ofthe valve 32, and when movement of the valve 36 stops with the ports 34 communicating with the vacuum space 31, the diaphragm 46 will' effect' sufficient additional movementof the valve 32 to move the ports 34 out of communication with the vacuum space 31.

When the acceleratorV pedal' 11 is depressed after the desired gearv shift has been made, the reverse operation will take place, the lever 61 being turned in a clockwise' direction about its pivot 68 (Figure 1)` until the projection 10 engages the upper end ofthe arm 64, whereupon further depression of the accelerator pedal will turn both levers 62 and 61 as la unit about the axis of the throttle shaft 63. These movements of the levers 62 and 61 result in movement of the valve rod 43 tothe left as viewed in Figures and 2, whereupon the vacuum space 31 will be definitely moved out of communication with the ports 34 and the latter will' be' uncovered by the inner end of the valve 36 to communication with the air passage 44. Air will thus flow through pipe 23 into the clutch motor 20 and the clutch springs (not shown) will move the clutch elements toward operative engagement.

Increases in pressure thus' taking place in the motor cylinder 20 will be duplicated-in the diaphragm chamber l524 (Figure 2) thus tending to balance pressures in the chambers 5| and 52 and rendering the spring 56 eiective for moving the valve 32 toward the right 'as viewed in Figure 2 whereby this valve will follow-up with respect to the valve 36. Upon the slightest initial engagement of the clutch elements a resistance to the movement of the clutch elements'and the parts connected thereto will be retarded, and such nitial retarding of the movement of the motor piston 2| results in an immediate rise in pressure in the vacuum end of the motor cylinder 20 and in the diaphragm chamber 52, in which case the spring 56 will quickly move the valve 32 slightly further to the right as viewed in Figure 2 to cut off or further restrict communication between the ports 34 and air passage 44. This causes the lessening orr complete cutting off of the admission of air into the motor cylinder 20 to slow up the movement of the clutch elements into operative engagement to prevent the grabbing ofthe clutch elements or the jerking or lunging of the vehicle. This functioning of the apparatus is fully described in the specification' in my prior Patent No. 1,964,693', referred to above.

The foregoing operations take place wholly under the control of the operator as determined by movement of the accelerator pedal 11 except when the vehicle is in high gear and travelling above a predetermined speed. Referring to Figure 3 it will be noted that when the transmission is in anygear position except high gear, the switch arm 99 will be in engagement with the contact |00. Accordingly, if the gear set is in .neutral position, or is in first, second or reverse V'rias operation, or

gears, aicircuit will remain closed from the source 9| through wires 93 and |05,'contact |00,-switch arm 99, wire |03, solenoid 39 and ground |04, and thence back to the source through ground 92. Under the 'conditions referred-to the energiza-` -tion of the solenoid 39 will hold the valve 38 (Figure 2) in open position so thatthe controlling of the clutch is solely dependent upon operation of vthe follow-up valve mechanismk in Figure 2 through operation of the-accelerator pedal 11.

"When the-vehicle is in high gear and travelling above a predetermined speed the solenoid 39 y will-not be energized. The shift into high gear will move the switch arm 99 out of engagement with the Contact |00 and into engagement with' `the contact 98in which-case the previously described circuit through the Vwire |05 will be broken;V If the vehicle is travelling below the predetermined speed referred to, fOreXampIe, 10 milesper hour, the switch arm 94 (Figure 3) will be in engagementy with the contact 95 in which case current will flow through wire 93 and switch arm 94, contact 95, wire 91 and contact 98 to the lswitch arm 99, and thence will be completed through the path previously described to energize the solenoid 39 and open the valve 38.`l VAbove the predetermined speed referred to this circuit will be broken at the contact95, the switch arm 94 under such conditions engaging the contact 96. Thus the solenoid 39 will be deenergized and the valve v38 (Figure 2) will be closed so that operation ofthe accelerator pedal to operate the folvlow-up control valve mechanism will haveno effecten the clutch. Y

Under the conditions just referred to the operator can release the accelerator pedal when in highV gear and above the predetermined speed referredV to and the clutch 'elements will be repoint at which the vehicle speed is reduced to v slower clutch'engagement is provided in first and reverse gears and very much slower clutch engagement `is provided after a shift down has been made 'from high to second gear. Referring to vFigure 3 it ywill be noted that when thevehicle is in either low or reversefgear the contact* |08 will be engaged by oneof the rings |06 or |01. Under such conditions a circuit will be completed from ythe source 9| through wires 93, |05 and H2, through the coil of the solenoid switch thence through vwire ||0, solenoid 60, Wire |09, Contact |08, ring |06 ory |01, and back tothe battery through grounds |02 and 92.

The solenoids 69 and are in series and the functioning of the solenoid will be described later. It will be apparent that when thegear set vis in either rst or reverse gears the solenoid 66 will be energized and this action results in movement of the'armature 6| (Figure 2) toward ential pressure when the solenoid (iii is deenergized and the spring 56 is under its normal.

tension.` Y i l-In' the clutch engaging'o-peratiori previously ydescribed the valve 36 moves toward the right as viewed in Figure 2 andthe valve32moves in the same direction during the follow-up action whichk occurs incident to the v*admission of Yair frointhe passage 44 throughtheportsi34 into the clutch inotorandinto the diaphragm vcham- 'ber52. `The increased loading ofthe spring 56 causes the valve 32 to follow-up to aslightly greaterextent than when the solenoid 60 isdeenergized', rthus tending 'to cutoff admission of air through the ports 34 slightlyjearlier'than would occur under thenormal tensioning of the spring 5.5.' This fact results in the'retarding .of the admission of air into the clutch motor with a resultant laggingv of the` clutch elements with respect tov the engagement of such elements when the Vehicle is in `a gear. ratio other than rst and reverse gears with the solenoid, Bldeenergized. Y This lagging of. the Amovement of the clutch elements' provides'the highlydesirable slightly slower engagement of the clutch 'elements when the vehicley isbeing startedfrom a standstillin either low or reverse jigears, thus preventing stalling of the motor or jerky Iclutch engagement.'

The most important featureof the present invention is the provision'of means for greatly retarding engagement ofthe clutch elements when a shift is made from highr to second gearso as toy permit the operator to depress the accelerator pedal and greatlyV acceleratethe engine speed prior to clutch engagement' so 'as to provide substantial synchronization of the. clutch elements beforerthey are brought into engagement.V The present construction' provides for. such result while at the same'time permitting normal relatively rapid clutch engagement after a shift has beenfmadeinto second gear from low gear.

Referring to Figure 3, it will be apparent that When the vehicle isin high gear and travelling abovethe predetermined speedreferred to the solenoid 39 will be deenergizemthe two parallel circuits for this solenoid bein'g broken atA the contact |00 and at thecontact 95. Assuming undersuch conditions thatV the operator desires to shift back intorsecond gear, he will close the overruling switch y |21 to complete a circuit through the solenoid 39 through wires 93,y |35', |28 and |30, and thence through.l the solenoid 39 and'grounds |04 and 92 to the battery 9|; The valve 138 (Figure 2) will immediately opens and with i'lheaccelerator` in released position the clutch will be immediately disengaged to permit the shift to be made. In connection vwith the overruling switch it will be obvious that, as previously'stated, thisswitch vmay be of any desired type and forms no part per se of thev present invention. y

The, clutchhaving been` released the operator will Yshift fromnh'ighjinto second gear and 'this operation moves the, shiftrail |1 to theright engagement with the contact |80 thus re-establishing a circuit through the solenoid 30 independently of the overruling switch which need no longer function. Moreover, the completion of the shift into second gear will engage the shift rail il with the contact |24.

It will be apparent that the solenoid will be energized only when the vehicle is in first and reverse gears, the coil of this solenoid being energized only if the contact |08 is engaged by j the lower position in engagement with the cony tacts |2| and |22.

With the vehicle travelling above 10 miles per hour, under the conditions being considered, the switch arm 94 will be in engagement with the contact 96. With the shift completed into second gear, therefore, a circuit will be completed through wire 93, switch arm 94, contact 06, wire |26, solenoid 88, wire |25, contacts |22 and |2|, wire |23, Contact |24, and ground |02, and thence to the source through ground 92. The immediate result of the shift into second gear, therefore, will be the energization of the solenoid 88 and as seen in Figure 2 this will result in moving the head end of the valve 96 across the passage 84 to restrict communication therethrough in accordance with the effective area of the groove 90.

So far as Vthe loperation is now completed it will be apparent that the clutch elements have been disengaged the shift will be completed into second gear, and the operator is ready to engage the clutch elements and accelerate the engine by depressing the accelerator pedal. This the operator will do in accordance with the previous description and the follow-up valve mechanism will function in exactly the same manner as before except that the following-up of the valve.

32 with respect to the valve 36 will be'greatly retarded due to the restriction of the flow of the air through the valve groove 90. Whereas under the previously described conditions the admission of air into the clutch motor will be controlled wholly by the follow-up valve mechanism, this will not now be true since the follow-up action of the valve 32 is dependent upon the admission of air into the chamber 52 and under the conditions being considered the admission of air is greatly restricted. Thus the ports 34 will be held wide open for communication with the air` passage but the admission of air through this passage will be greatly restricted thus providing a very slow movement of the motor piston 2| to the clutch engaging position as compared with the normal functioning of the follow-up valve mechanism.

Therefore it will be apparent that when a shift is made from high to second gear a substantial time'interval elapses between depression of the accelerator pedal and operative engagement of the clutch elements and this interval is sufcient to permit substantial engine acceleration to approximately synchronize the speed of the clutch elements before they are'brought into clutch engagement to take place under such condition without any jerking or lunging of the vehicle.

The energization of the solenoid 88 is dependent upon deenergization of the coil of the solenoid so that the head |20 will be `vin engagement with the contacts |2| and |22. The solenoid obviously is deenergized when the important functions.

46 `eeaefis vehicleis in high gear, and with thewvehicle trayellingabove apredetermined speed the only thing necessary to energize the solenoid 88 is the movementof the shift rail vto the vsecond gear `position to contact Lwith 'the spring contact 21|,v This is the only movement necessary, therefore, to effect energization of 'the solenoid 88 to provide the choking action which isy employed for providing slow clutch engagement when the shift/is made from Ahighgto second gear. When the vehicle is in lowor reverse gears, `the'solenoid is energized in the 'manner `previously described and accordinglyl no circuit can be completed through the solenoid 88.

Referring to Figure 4 it will beseen that when the solenoid coil ||2 is energized when the vehicle is in `firstvor reverse gears, `the head |20 is in contact with the `flange IIB, `substantially out of engagement with the contacts |2| `and |22. Assuming thatrthe vehicle is being started from a standstill in lowY gear the parts of the solenoid switch will occupy the positions shown in Figure 4 and after the Vehicle has gained sufficient speed in low gear the operator will release the accelerator pedal to disengage the clutch, then make the shift into second gear and operate the accelerator pedalto effect clutch engagement. As soon as the shiftvis made out of low Vgear the circuit through the solenoid 60 isbroken at the contact |08 to restore lthe normal tension of the spring 56l (Figure 2) and the circuit through the coil of the solenoid also will be broken. However, the head |20 will not immediately dropintcengagement with the contacts |2| and |22 owing to the dashpotl action of the `armature IM (Figure 4) moving in the oil in the space 'I'he armature ||4 is` of lan `externa-1 diameter slightly smaller thanV the internal diameter of the core ||3 or theperiphery of the armature ||4 is grooved, thus providing for the restricted passage of yoil past the armature ||4 as the latter moves downwardly by gravity together with the elements connected Ythereto when the coil ||2 is deenergized.

`The timeninterval required fory movement of the head |20 downwardly into engagement with the contacts |2| and |22 may be regulated by properly designing the solenoid switch to determine the rate of flow of oil or other liquid past the armature I4. In actual practice it has been found that a four second interval `between deenergization of the coil ||2 and engagement of the head |20 with the contacts |2| and |22 is highly desirable. This time interval serves two In the first place, it permits ample time between the breaking of the circuit through `the coil ||2 when the shift is made out of low gear and the completion of the shift into second gear and the effecting of clutch engagement before the head |20 engages the contacts |2| and |22, Therefore the energization of the solenoid 8B andthe restriction of flow of air through the follow-up valve mechanism is prevented during the normal shift from first to second gears but is provided for when the shift i kclutch motor.

' putthe gear set in'low. gear, accelerate the engine and eiect clutch engagement,and ywill then nd it necessaryl to delay ,clutchengagement insecl ond Vgear because :of traffic conditions. .Under such conditions theengine willlose speed which has been gained ln'low gear sothatrelativeliI rapid clutch engagement insecond gear is impracticable. 1

.; With ther presentdevice a delay. of4 four seclonds fin completingtheoshift` into. second gear and the. completing v thereafter of vtheengagement vof the clutch elements will result in the engage- .ment of the headlZll with Ythe contacts l2l and |22, and accordingly thefsolenoidwill be ener.-k gized `to choke the .admission vof. air-` into` lthe If, Iunder such conditions, the operator thendepressed theaccelerator pedal too tiony in the manner previously describedi tol effect relatively slowclutch engagement.v V, .i l x From theforegoing iinwillbe apparentgthat verse gears by the compression of the spring 5G, thus, preventing stalling A-ofthefengine or jerky .clutch engagementV when the vehicle is being started from ai standstill. When anormal shift is vmade from iirst Yto second gear and the engine acceleratoris depressed to permit clutch engagement, the rate of ,this .engagementis permitted to, take place normally in accordance with the normal functioning ofthe follow-up Valve mechr anism. If the operator delays too long incomypletingthe shift into second gear anddepressing .the present clutch; control system yprovides for *y efficient clutch engagement under all conditions i ,of motor vehicle operation., Somewhat slower clutch engagement is provided 4iniirst andrepower device for releasing the clutch elements for; controlled movement into engagement with each other, auxiliary control means for causing a relative lagging of the movement of the clutch elements into operative engagement upon operation of said control mechanism to deenergize said power device, and a second auxiliary control 'means for eiecting a lagging 0f the movement `ofthe clutch `elements into operative engagement and operable only during inoperativeness` of said first named auxiliary means.

, "2. A clutch control mechanism comprising a power device connected to the clutch, control .mechanism for energizing the power device to disengage the clutch and for deenergizing the powerdevice for releasing the clutch elements forncontrolled .movement into engagement with each other, auxiliary control means for causing la relative lagging ofthe movement ofjthe clutch elements into operative engagement upon operation yof saidA control mechanism to deenergize said power device, a second auxiliary control means operativefor eecting-arelative lagging of the Amovementfoi the-clutch elements into loperative engagement, andk meansffor rendering said second auxiliary control means operable only during inoperativeness'of theA l'lrst named aux.-

iliarycontrol means. L.

' 3. A clutch control mechanism Acomprising a vpower device connected to the clutch, control mechanismfiorenergizing the power device -to disengage then-clutchand forigdeenergizing the power Adevice for Areleasingthe clutch -elements .the accelerator pedal kandthe yenginefloses sub- I stantial speed, the choke valve 86 will comerinto n .operation and provide the desired relatively slow clutch engagement. l. i

It will be apparentthatthesolenoid8S-tis :inoperative when theshift is Vmade V intomhigh gear. Y, The circuit for ,this` solenoidis always dependent yupon the closing v,or the4 circuit `across the contact E24 and shift railwl and this circuit` is broken when the shift is made into higljigear .and accordingly the` rate of Yclutchengagement `is determined solely. by operation ofthe followup 'valve mechanismand lclutch engagement may ltake place quite rapidly Aunder suchA conditions.

The principal function of` thelsolenoid valve :l lil iswfornthe shift baci; from high `tosecond gear rin the vmanner previously described, the choling rof the admissionlof air into lthe clutch motor rpreventing the controlling of the-,ratev of. clutch Engagement by the Voperation of the follow-up valve. mechanism in the normalmanner, the rate .of clutchnengagement being very mucho'retarded for controlled movement into engagement with each other, auxiliary controll means for .causing arelative lagging of the movement oi the. clutch elementsintonoperative engagement upon operationA of said control mechanism to deenergize said power device, va second auxiliary` control means operative for effecting a relative lagging of the movement of the clutch elements into op- ;erative engagement, a control device for said second auxiliary control means, andmeans for rendering said control device ineffective for ren- :dering said ysecond auxiliary control means op'- verative until after the .rst named auxiliary control means has been inoperative for at least `a lpredetermined length of time. I1 l 4. A yclutch control mechanism comprising a power device connected to the clutch, control mechanism for energizing the power device to ,-disengage the clutch andY for deenergizing the power. device for releasing the clutch elements .in comparison withlthe normal rate to allow n ample time for the synchronizationof the yclutch elements lthusprov idir ig n for very, smooth clutch engagement when shifting from high to second gear,

It is tote understood .that luie' fornithe ir'iventionY herewithV shownand describedl vis togbe taken als a preferred example of the same and thativarious changesinwthey shape/size, and ari vrangement of parts may be resorted tofwithout eparting` from the spirit ofl the'invention or the SCOP@ of the Subioiaedlaims..

rclaml. f a A clutch .control mechanism comprisingl a power, ydevice connectedlyto the1 clutch, control mechanism for energizing the power device to for controlled movement into engagement with each other, auxiliary control means for causing Ala. relativelagging oi themovement of the-.clutch elements into operativeengagement upon operation ofsaid control mechanism `to deenergize said ypower device, and an electro-magnetic device energizable for effecting a lagging` of the movement of the clutch elements intooperative engagement and capable of energization only during' inoperativenessof said auxiliary control .5. A- clutch control'mechanism comprising a .gizable for :effecting fa relative lagging 'of the .movement 'of the fclutch `'eier-nente into .operative engagement, iand a circuit vfor fsaid electro-mag- .neti'c device 4including a switch varranged .to be `closed only when vsaid auxiliary control mfeans .is inoperative.

.6. 4A clutch control .mechanism comprising ai power `device connected tothe '.clutch, :control mechanism for energizing `,the .power fdevice Yto `fdisengage the clutch and for :deenergizing the power device for releasing the clutch lelements for controlled movement into engagement with each other, auxiliary control means for causing Ia relative lagging of the movement ofthe clutch elements into operative engagement upon roperation of said control mechanism vto =deenergize said .power device, an electro-magnetic device -energizable for efecting a .relative lagging =of the movement of the clutch elements into 'op- `erative engagement, a circuit vfor .said electromagnetic device including a fswitch, and a `control device operative for open-ing said switch when .said auxiliary control means .is operative, said switch 'being biased for movement lto closed Iposition and said control device being construct- ,ed `and arranged .to delay movement of said switch to closed position.

'7. A clutch control mechanism comprising va .power .device connected -to the clutch, a control mechanism ffor energizing the power fdevi'ce `to disengage the clutch .and for decnergizing the power device for `releasing Ithe :clutch yelements 1for controlled movement into engagement with each other, a pair of electro-magnetic devices separately energizable 'to effect a.'lagging =of the movement of the clutch elements finto :operative engagement, and means for preventing .the-'closingof a=circuit through -one ofsaidfelectro-magn'etic devices when 'the other electro-magnetic vrdevice is energized.

8. lA clutch controllmechanism .comprising fa )power device connected to the clutch, a 'control mechanism .for 'energizing 'the .power device to disengage the 'clutch `'and fior deen'ergizing the -power device for releasing thefclutch elements rfor controlled movement into l'engagement@with each other, `a pair 'of electro-magnetic Ldevices separately energiza'ble to .effect Aa .lagging 'of the movement of the fclutch elements .into operative (engagement, rand vmeans -for ,preventing the -clos f ring-ofa circuitfthrough one of .saidielectro-mag- .n'e'tic devices when the other electro-magnetic sdevice is energized, said means being constructed .land arranged fto :prevent Jenerglzationof the first mentioned electro-magnetic `device un-til vafter ascenso lpower vrdevice for releasing .th'e ycintch l'elements rior .controlled .movement .into engagement with each other., :a pair offJelectmo-magnetic ldevices separately 'energrlzable 11o eiect 1a tagging of the imovement -of :the .clutch elements .into .operative .feng-agement, .a :switch for. the Acircuit .of one of `said electroema'gneti'c devices :biased to closed position, and means for holding saidswitch .open when fthe 'other felectroma'gnetc .device is Lener- |`gzized, f'sai'd means con'rprisirxgl .a 'third .electromagnetic device l.connected .to :said :and .ar-

-rasnged in .series with zsaid other electro -magnetic `device whereby llenerigizati'on `of the latter prevents the closing of 'said 11. .'A clutch control mechanism :comprising a power fde'vice .connected 'to the clutch, a control 4mechanism '.for'en'ergizin'g the ."fpower device to disengage the c'lutchxand lior ricenergizing the Ipower :device-for releasing theclutchelements for controlled movement iinto engagement `with each other, :a -pair of lectro-magnetic devices separatelyienergizable Lto efte'ctra lagging of the movement -o'f the clutch elements .into .operative .engagemenafaswitchfor fthe circuit .of one of said 4elcetro-magnetic .devices biased `to closed position, means Vfor holding ysaid :switch open when lthe vother yelentro-magnetic :device is energized, .said Lmeans ncomprising '.a .third electromagnetic :de-

vice connected to said :switch `and. arranged .in :series with `said :other lelectro-magnetic device Iwhereby `energization fof the ilatter prevents the -closing Aof saidfswitchfand .means Afor delaying the closing 4ofi-said switch vupon deenergization of said l#third electro-magnetic dev-ice.

'12. A clutch rcontrol :mechanism comprising a fluid pressure operated power device connected Ato the-clutch, acontr'ol 'valve mechanism for connecting the power device to `aseurce fof pressure dinerentialto disengage the-c1utch=and ifor establishing pressure equalizationfinitihe power device ffor releasing the-clutch elements for controlled 'movement into engagement' with-each other, auxiliary -control means for changing the functioningof `said/control valve mechanism 'to. relatively 1retar'dlthe establishmentof pressure equalization in said power 'device lto A'cause 'a relative lagging :said :other electro-'magnetic .device has been "detion, and `means ifor .holding said .switch -open when the other electro-magnetic device is-'energized `10. 4A clutch icon'trol imeohanism 'comprising 'a power device connected to Vthe clutch, acoritrl mechanism for energizing .the lpower .device to vdisengage the .clutch .and for I.deenergizing fthe 'of 'themovement of theclutc'he'lements -intooperative engagement, and a `vsecond auxiliary con- 'trol means `for l`re'tarding the establishment of pressureequalizationfin saidpower device to effect a lagging ofthe'movementof'the clutch elements into operative lengagement, -sai'd second Aauxiliary control means V"boing operable Aonly during in- -operativeness ofsaid -drs'tnamed auxiliary means. 11'3. A clutch control mechanism comprising a fiiuid pressure operated 'power jdevice connected ito'-thefcluten-a control valve mechanism for con- -necting'the :power 'device `to `a source of pressure 'differential to disengage the'cluth andffor establishing pressure equalization -in the power de- 'vice ffor releasing-the clutch 'elements "for yconftrlle'd `movement Ainto engagement with each other, auxiliary control means for changing the fi'unctioning o'f vsaid fcontro1-va1ve mechanism to Irelatively Iretard the establishment Aoi pressure equalization 'in said power device tovcause a relative lagging -of the movement of the clutch yelements into :operative engagement, and -a second auxiliary fcontrol means for -re'tarding the establishment of pressureequa'lization in -said power device to effect a lagging of the movement'of the clutch `elements Vinto Aoperative engagement, Vand means for "rendering vsaid 'second auxiliary control m'eans operable onlir jduring inoperativeness of'the -iirs't named auxiliarycontrol means.

14. A clutchcontrol mechanism comprising a fluid pressure'operated power devicey connected tothe clutch, a control valvemechanism for connecting the lpower device to aj sourceof pressure diierentialto disengage the clutch and for establishing pressure equalization in the power device for releasing the clutch elements forcen-` trolled movement into engagement with each other-,auxiliary control means for changing` the functioning of saidv control valve mechanism ,tov

Vvice vineffective for rendering, said second auxiliary control means operative` until after the rst named auxiliarycontrol means has been inoper' ative fior V.at

time.

15. A clutch ycontrol mechanism-comprising a fluid pressure operated power.` device connectedvto least a predetermined length of the clutch, a control valve mechanism for 'con-f necting the power Adevice to a source of pressure diierentialto disengage the l,clutch and forestablishing pressure equalization inI the rpower device for releasing the lclutch elementsfforvconf.

trolled z movement. into engagement with each other, auxiliary control means for changing the functioning. of Said'control Valve mechanism to relatively' retard rthe establishment of kpressure equalization in said power device to cause a relative lagging of the movement of the. clutch eleequalization in said power device to cause a relative lagging of the movement of the clutch elements into operative engagement, an electromagnetic device energizable for effecting a relative lagging of the movement Ao2 the clutch elements into operative engagement, a circuitior said electro-magnetic device including a switch,V and a control device operative for openingl saidl switch when said auxiliarycontrol means is operative, said switch being biased for movement to closed position and said control device being con# structed and arranged to delay movement of said switch to closed position. Y l f i8. A clutch control Vmechanism comprising a fluid pressure operated power device, a follow-up Acontroly valve mechanism for connecting the power device vto a source of pressure diierential to disengage the clutch and for establishing pressure equalization in the power device for releasing the clutch elements for controlled movementl in said power device upon a clutch element releasing operation of saidv valvey mechanism to elect a lagging of thejmovement oi the clutch elements into operative engagement, and means ior preventing the closing of a.-y circuit through one oi vsaid electromagnetic devices when other device is energized.v j

19. A clutch control mechanism comprising a kfluid pressure operated power device, ai'ollpw-'up mentsintooperative engagement, andan ele'ctro-v l magnetic device energizable for eiecting'a lagging of the movement of. the'clutch elements into f connecting the power device toa source of vpres'- Voperative'engagement land capable of energization only during inoperativenessiof said auxiliary control rvalve mechanism for connecting: the .power device to a source of pressuredifferentiai to disengage the clutch and for establishing pressure equalization in the power device for releasz ing the clutch elements .for controlled movement into engagement with each other, Va pair of electro-magnetic y devices separately energizableV to retard the establishment of pressure equalization insaidpower deviceupon a clutch element'A releasing operation ,of said valve mechanism ,toeect a lagging of the'movemen-t or" the clutch elements into operative engagement, and means sure diierential to .disengage the" clutch and for l.

ments into operative engagement, an 'electrof magnetic device' energizablefor effecting' a rela` tive laggingloi the `Ymovement of theciutcliA elements. intov operative engagement, and a circuitfor sai'd'electroma'gnetic device including a switch arranged to be. closed yonly when said' auxiliary control'means is inoperative; l Y

'17; A clutch control'.mecl'iani'sni` comprising a iluid pressure operated power device connected tothe. clutch,` a control valve mechanism for connecting'the power device to a source of pressure differential toldi'sengage the clutch and for establishing pressi-irefeqalizationl inthe power device for releasing the clutch elementsffor controlled movement into engagementfwith each other,` auxiliary' control means for changing the function-ing -oflsaid control valve mechanism? to relatively'retard the establishment ofpressure for preventing the closing of. a circuit through" the first named electro-magnetic device until aiterthe other electro-magnetic device has-been.

VVd eener'giaedifor a predetermined' length of time.

, 20. A clutch control mechanism comprising a `fluid motor, a control valve mechanism therefor operable for 'connecting said motor to a sourcelof pressure` differential to disengage the clutchand for establishing pressure 'equalization inysaid motor to release the clutch elements for move"- ment into operative engagement, means for causing a follow-up action of said valve mechanism comprising a pressure responsive element having. a pressure chamber communicating with the-mo'- tor,; and-a spring urging saidpiessure responsive element in one direction against thefdiierential pressure establishedy in said chamber, auxiliary control nieansfor varying the follow-up action of said" valve mechanism by changing the loading of said spring to retard the establishment of pressure equalization in said motor upon a clutch element releasing operation'of saidvalve mechanism, a second auxiliary control meansfor vre-v tarding vthe establishment'of pressure 'equalieation in said motor, and meansfo'r rendering said second auxiliary -controll `mear-is'4 operable" only during inoperativeness' of the first `named' auxiliary control means. A 'l the 2l. A clutch control mechanism comprising a duid motor, a control valve mechanism therefor operable for connecting said motor to a source of pressure diierential to disengage the clutch and lfor establishing pressure equalization in said motor to release Vthe clutch elements for movement into operative engagement, means -ior causing afollow-up action of said valve mechanism comprising a pressurev responsive element arranged-between two chambers one of which is a p-ressure chamber communicating with the motor, and a spring urging said pressure responsive element in one direction against differential pressures in said chambers,v auxiliary control means for varying the follow-up laction of said valve mechanism by changing the loading of said spring to retard the establishment of pressure equalization in said motor upon a clutch element releasing operation lof said valve mecha nism, a second auxiliary control means for retarding the establishment ofpressure equalization in said motor, and means for rendering said second auxiliary control means operable only duringinoperativeness oi.v the iirst named auxiliary control means, said last named means being constructed and arranged to render said second auxiliary control means operative only after said `First named` `auxiliary control means has been rendered inoperative for a predetermined length oitime. v

22. A clutch control mechanism comprising a fluid motor, a control valve mechanism therefor operable for connecting said motor to a source of pressure differential to disengage the clutch'and for establishing pressure equalization in said motor to release the clutch elements for movement into operative engagement, means for causing a follow-up action of said valve mechanism comprising a pressurel responsive lelement arranged betweenltwo chambers one of which is a pressure chamber communicating with the motor, and a spring urging said pressure responsive element in one direction against diierential pressures in said chambers, an electro-magnetic device for changing the loading of said spring to alter the followupaction ci said valve mechanism to retard the establishment of pressure equalization in said motor andA effect a lagging of the movement oi the clutch elements into operative engagement, a second electro-magnetic devicefor retarding the establishment of pressure equalization insaidmotor to eiect a lagging of the movement of the clutch elements into operative engagement, and means for maintaining a circuit through the second electro-magnetic device open until a predetermined lengthv of time yhas elapsed after the dcenergizatio-n of the first named electro-magneticdevice. l.

123. Aclutch control mechanism comprising a uid motor, a control valve mechanism therefor operable for connecting vsaid. motor to a source oi pressure diiferentialto disengage the clutch and for establishing pressure equalization in said motor to release the clutch elements for movement into operative engagement, means for causing a follow-up action loi said valve mechanism comprising al pressure responsive element arranged between two chambers one of which is a pressure chamber communicating with the motor, and a spring urging said pressure responsive element in one direction against differential pressures in said chambers, a pair of electro-magnetic devices separately energizable to retard the establishment :of pressureequalization in said motor to etect a lagging of the movement of the clutch elements into operative engagement, a'switch for the ycircuit of one of said electro-magnetic devices, and

means for maintaining said switch open when the other electro-magnetic device is energized, said last named means being constructed andV arranged to prevent the closing of said switch for a predeterminedlength oi time after the deenergization of said other electro-magnetic device.

24. A clutch control vmechanism for a motor vehicle having a clutch, and a transmission including shiftablemeansfo'r providing'different gear ratios, comprising' a powerv device connected' to the clutch, a control mechanism for. energizing the power device to disengage the clutch and `for deenergizing the power device for releasing the clutch elements for controlled movement into engagement with each other, a pair of auxiliary control means respectively operative when the transmission shiftable means `is operative for providing different gear ratios,for,causing a relative lagging of the movement of the clutch elements into operative engagement upon operation of said control mechanism to deenergizesaid power device, and means for rendering one of said auxiliary controlmeans inoperative unless the other auxiliary control means is inoperative..

25. A clutch control mechanismior a motor vehicleA having a clutch,` and Va transmission including shiftable 'means for .providing dilerent gear ratios, comprising 'apower device connected to the clutch, a controlmechanismfor energizing .the power device to disengage the clutch andior deenergizing the power device for releasingthe clutch elements for controlled movement into engagement with each other, a pairof auxiliary control means Arespectively operativeV when the iary control means has beeninoperative over a predetermined period of time.

26. A clutch control'mechanism for a motor vehicle having a clutch, and a transmission including shiftablemeans forproviding diierent gear ratios, comprising a power device connected to the clutch, a control mechanism for energizing the power device to disengage the clutch and for deenergizing the power device for releasing the clutch elements for controlled movement into engagement with eachv other, a pair of electromagnetic control devices respectively operable when` the transmission shiftable means is respectively positioned for providing ,different gear ratios, for causing a relative lagging of themovef ment of the clutch -elements intooperative engagement upon operation of said control mechanismV to deenergizesaid power device, a switch in the circuit of fone of said electro-magnetic de,- vices, and means for holding said switch open when the other electro-magnetic device is operative,to prevent operation of said first mentioned electro-magnetic control device.

27. A clutch control mechanism for aymotor vehicle having a clutch, and a transmission including shiftable means forproviding different gear ratios, comprising a. power device ,connectedf to the clutch, av control mechanism forenersizi ing the power device to disengage the clutch and for deenergizing the power device for releasing the clutch elements for controlled movement into f engagement with each othr, a pair of electromagnetic control devices respectively operable when the transmission shiftable means is respectively positioned for providing different gear ratios, for causing a relative lagging of the movement or" the clutch elements into operative engagement upon operation of said control mechanism to deenergize said power device, a switch in the circuit of one of said electro-magnetic devices, and means for` holding said switch open when the other electro-magnetic device is operative, to prevent operation of said rst vmentioned electro-magnetic control device, said last named means being constructed and arranged to prevent said switch from closing until the second mentioned electro-magnetic device has been inoperative for at least a predetermined length of time.

28. A clutch control mechanism for a motor vehicle having an engine, a throttle and an accelerator connected thereto, a clutch, and a transmission having shiitable means movable to provide a transmission condition normally used when the vehicle is started from a standstill and movable to provide a second transmission condi-` tion normally used after the vehicle has gained momentum, comprising a power device connected to the clutch, a follow-up control mechanism for the power device having connection with the accelerator and throttle and having operative asso'-v tive engagement upon a clutch element releasing operation of the control mechanism, and ymeans operable when the rst named auxiliary control device is operative for rendering the second named auxiliary control device inoperative.

29. A clutch control mechanism for a motor vehicle having an engine, a throttle and an accelerator connected thereto, a clutch, and a transmission having shiftable means movable to provide a transmission condition normally used when the vehicle is started from a standstill and movable to provide a second transmission condition normally used after thevehicle has gained momentum, comprising a power device connected to the clutch, a follow-up control mechanism for the power device having connection with the ac-l celerator and throttle and having operative association with the power device to cause the latter to follow up with respect to the accelerator pedal, a pair of auxiliary control devices one operative under the iirst named transmission condition and the other operative under the second transmission condition for causing a relative lagging of the movement of the clutch elements into operative engagement upon a clutch element releasing operation of the control mechanisnand means operable when the iirst named auxiliary control device is operative for rendering the second named auxiliary control device inoperative, said last named means being constructed and arranged to prevent operation of the second v named auxiliary control device until after the rst named device has been inoperative for a predetermined length of time.

S0. A clutch control mechanism for a motor vehicle having an engine, a throttle and an accelerator connected thereto, a clutch, and a transmission having shiftable means movable to provide a transmission condition normally used 'when the vehicle is started from a standstill and movable to provide a second transmission condij tion normally used after the vehicle has gained momentum, comprising a power device connected to the clutch, a follow-up control mechanism for the power device having connection with the accelerator and throttle and having operative as# sociation with the power device to cause the lat-vr ter to following up with respect to the accelerator pedal, a pair of electromagnetic control devices one operable under the rst named transmission condition and the other operable under the sec- Y ond transmission condition for causing a relative lagging of the movementof the clutch elements into operative engagement upon a'clutch element releasing operation of said control mechanism,

Aand means in the circuit of the rst mentioned.v

electro-magnetic device for preventing operation of the second mentioneddevice when thenrst provide a transmission condition normally used when the vehicle isstartedfrom a standstill and movable to-provide a 'second transmission condi` tion normally' used after the vehicle has gained momentum, comprising a power deviceconnected to the clutch, a follow-up control mechanism for the power device having connection with the aclcelerator and throttle andhaving operative assoy ciation with the power device to cause the latter to follow up with respect to the accelerator pedal,

means for preventing the closing of said switch for a predetermined length of time after deenergizationA of the iirst mentioned electro-magnetic device.

32. A clutch control mechanism comprising a r power device connected to the clutch, control mechanism for energizing the power device to disengage the clutch and for deenergizing the power device for releasing the clutch elements l for controlled movement into engagement with trol means operative, and operating means fory rendering the other control means operative, said last named operating means comprising a time delayed devicev for rendering the second mentioned control means operative only after a predetermined period of inoperativeness of the irst mentioned control means.

EDWARD G. HILL. 

